Tool for removing wire insulation



Oct. 26, 1948. p BASS 2,452,423

TOOL FOR REMOVING WIRE INSULATION Filed Oct. 10, 1945 INVENTORL PatentedOct. 26, 1948 UNITED STATES PATENT. ori ice 2,452,423 TOOL FOR REMOVINGWIRE INSULATlON Arthur 1?. Bass, Newark, N.'J.

Application October 10, 1945, Serial No. 621,471

This invention relates to an improved power actuated tool for removinginsulation coatings from electrical conductors; and the invention hasreference, more particularly, to a novel tool especially adapted toremove insulation coatings of enamel, glass, hard insulation materialknown to the art under the trade name Formvar, and all other kinds ofhard insulation substances.

The invention has for an object to provide a novel tool mechanism forthe purposes stated which is adapted to be power driven, preferably byan electric motor; said tool mechanism comprising a rotatable headhaving an axial pas-sage to receive an end portion of an insulated wireto be operated upon; said head being provided. with opposed movable toolmembers disposed radially to the axis thereof, and tool controllinglever means suitably weighted to respond to centrifugal force, wherebyto automatically move the tool members, when the head is rotated, from anormal initial retracted position into operative engagement with aninsulated wire to be operated upon.

The invention has for another object to provide a tool mechanism of thecharacter and for the purposes above stated which is of very simple andcompact structure, whereby the, same is especially well adapted toprovide a portable tool which can be both easily manipulated in use andconveniently carried about by the user.

An illustrative embodiment of the invention is shown in the accompanyingdrawings, in which:

Fig. 1 is a front elevational view of the tool according to thisinvention; Fig. 2 is a fragmentary side elevational view; Fig. 3 is afragmentary longitudinal sectional View of the tool, with parts shown inelevation, the tool members and controlling lever means being disposedin retracted normal initial position. said view being drawn on anenlarged scale; Fig. 4 is a view similar to that of Fig. 3, but showingthe tool members and controlling lever means in operative positions;Fig. 5 is a. fragmentary horizontal sectional view, taken on line 5--5in Fig. 3; Fig. 6 is a fragmentary horizontal view, taken on line 66 inFig. 4: and Fig. 7 is a horizontal sectional view similar to that ofFig. 6, but showing modified forms of tool members.

Similar characters of reference are employed in the above describedviews, to indicate corresponding parts.

The novel tool according to this invention comprises a head member ID ofsuitable shape having an axially aligned shank portion ll of substan-#tially reduced diameter. Entering from the free 8 Claims. (01. -93) endor top of said head member H3 and extending downwardly therethrough andinto said shank portion 1 l for a suitable distance is an axial passageor bore I2, the diameter of which is some what in excess of the maximumdiametric size of insulated wire which the tool is designed to operateupon. Where said axial passage or bore !2 opens out of the free end ortop of said head l0, the same is preferably shaped to provide aninverted conical or funnel-shaped mouth por;

tion It. Formed in the head member ill to intersect the axial passage orbore 52 and to extend radi ally outward therefrom, respectively fromopposite sides thereof, are slideway passages I M. Formed in the headmember if! toextend transversely therethrough and downwardly from therespective slideway passages it, in aligned rela tion to thelongitudinal axes 'of the latter, bearing slots l5. Mounted in therespective slideway passages it, so as to be longitudinally andreciprocably slidable therein, are opposed tool members it. Each toolmember H5 is provided with abifurcated tail end portion at its outer endadapted to'provide a slot portion I! in alignment with the adjacentbearing slot l5,

Connected with the head member l8 and its shank portion l I is a toolcontrolling lever means so constructed and arranged as to respond tocentrifugal force induced by rotation of the head member, whereby tomove the tool members from a normal initial retracted position into ope:ve engagement with an insulated wire entered in the passage or bore l2of said head member. "An illustrative and preferred form of such toolcomtrolling lever means, as shown, comprises primary lever members l8mounted respectively in the respective bearing slots !5, and pivotallyrelated to the head member I'd by fulcrum pins it which extendtransversely'through the latter and across said bearing slots. Eachprimary lever member I8 is provided with an upper arm Elli suitablyshaped at'its free end to provide a cam-finger 2| which is entered inthe slot portion ll of the adjacent tool Iii, so as to bear againstthebo'dy of saidtool. Extending transversely through the tail endportion of each too-1 it, to cross its slot mounted byits'hub portion El on the-thanlrnporii tion ll of the head member Ill is a cross-head 25,to the oppositely extending arms of which are respectively pivotedsecondary lever members 26. The upper ends of said secondary levermembers 26 terminate in weighty bifurcated knuckle portions 21 whichreceive and to which are pivotally connected, by pivoting pins 28, therespective lower end portions 29 of the primary lever members l8. Saidpivoting pins 28 project exteriorly from the knuckle connections thusformed, 'and interconnected between corresponding end portions of saidpivoting pins are pull-springs 30. Said pull-springs 30 yieldablyretract the primary and secondary lever members to normal initialpositions substantially parallel to the'longitudinal axis of said headmember l and. its shankiportion H, and stopped against the sides of thelatter, whereby to normally dispose thet'oolm'embers |'6 in an outwardlyretracted normal -initial out of service or inoperative position (seeFigs. 3 and 4.).

In'one form thereofpas shown in Figs. 1 to 6 inclusive, the toolmembersare respectively so formed thatone thereof constitutes a work embracingand backing tool, 'for which purpose its forward operative end isindented to provide a work-receiving seat 3| having convergent sides,said seat being aligned with the longitudinal axis of an insulated wireentered in the passage or bore l2 for treatment. The other tool memberis formed at its forward end to provide a beveled insulation shaver orcutter element -32 havin a sharp cutt ng edge also al gned with thelongitudinal axis of an-insulated wire entered in the passage or bore 12for treatment.

The tool is adapted to be driven by suitable application of power to theshank portion ll thereof, whereby to rapidly rotate the same.Preferably, and especially in the portable type of the tool as shown,the power source is provided by an electric motor 33, to the armatureshaft of which said shank portion H issuitably connected or coupled, ase. g.-by a coupling connection 34 as shown (see Fig.1). The motor isprovided with any suitable-form of manually operative switch 35,wherebyservice of current thereto from a power source may-be controlled.

In the use of the tool, the insulated wire W to-be treated is: insertedin the passage or-bore 42, so that the end portion thereof from whichthe insulation is to be removed passes downwardly between the outwardlyretracted tool members It. The wire W being thus positioned in the tool,powerisapplied to the latter whereby to rapidly rotate the same whilethe operator holds the wire against rotation. In the electric motordriven type of-the tool as shown, afterthe wire W is inserted andheld-against rotation, the operator closes the swit'ch 35, whereby themotor functions to rapidly rotate'the shank portion H and head member IDabout the axis of'the wire. Such rotation of the shank portion and headmember subjects the weighty knuckle Joined ends of the primary andsecondary lever members |826 to the eifectsof centrifugal force, wherebysaid knuckle joined ends are impelled to swing outwardly; thus rockingthe primary levermembers about their fulcrum pins I9, and therebycausing an in-swinging movement of the cam fingers 2| thereof.

The in swinging movement of said-cam fingers 2| exerts inward thrustupon thetool members I6, whereby to o'peratively engage the wire W. Onetool member engages "one side ofsaidwire Wksoasto receive the same inthe seat 3| thereof, whereby to embrace and back the wire subject to theinsulation shaving or cutting action of the other tool member, as theshaver or cutter element 32 of the latter bears against the oppositeside of the wire. As the tool members i6 revolve about the wire, whilesubjected to the constant inward thrust exerted by the centrif ugallyimpelled lever members 18-46, the shaver or cutter element 32 willrapidly shave or cut awa the hardinsulation coating so .a'sto' quicklybare the underlying metal wire. During such operative action of the toolmembers IS, the user gradually draws the wire W outwardly from thelpassageorbore-LZ so that the end portion thereof is "caused 'totraverse the zone of action of the tooli'memb'ers, and consequently sothat the latter may efiectively attack and remove the insulation"alongthe'entire length of the end portion of the wire which is desiredto be bared.

After a wire has been treated and withdrawn from the tool as abovedescribed, the operator releases the switch 35 to interrupt service ofcurrent to and thus stopping the motor, whereupon :the springs 33retract the lever members |8?.6 to normal initialpositions,thus-out-swinging the cam-fingers '2 I. Out-swinging movement of the camfingers zl engages the same with the retractor cross-pins 22 of thetoolmembers It, whereby the outward movement :of said cam fingers istransmitted to the latter so as to withdraw or retract the same tonormal inoperative or out of service positions.

The opera-tive ends of the tool members l6 may be variously modified.For example, instead of the cooperative shaver and seat arrangementabove described, the operative ends of the tool members maybe in theform of abrasive'elements or grinder members36, as shown in Fig. 7.

It will be understood that some changes'could be made in theconstruction and "arrangement of 'the tool without"departing'from thescope "of this invention as de'finedin the following claims. It istherefore intended that all matter contained in the foregoingdescription or shown the accompanying drawings shall be interpreted asillustrativeand not in a limiting sense.

I claim:

1. In a'tool for the'purposesdescribed, a head member having-an axialshank, said'head member and shank being adapted to be rotated about thelongitudinal axis thereof, said head member and shank having an axialwire receiving bore and diametrically aligned slideway passages radialto said bore,-cpposed tool members slidably mounted in. said slidewaypassages, toolm'ember controlling lever means. pivotally connected withsaid head member adjacently below said slideway passages, whereby toprovide upper and lower. arms, and means to connect said tool mem bersrespectively with said upper arms subject to movement thereby toward andfrom said bore, the lower arms'of said lever means being responsiveitooutswinging centrifugal force when the-head member is rotated, wherebysaid upper arms automatically move said tool members from a normalinitialretracted position into operative engagement with a wireinsertedin said-bore.

2. Atom for the purposes described as defined in claim 1, wherein saidtool members are "provided at their operative ends with abrasive grindermembers.

3. In a tool for-'the'purposes described as defined-in claim 1, whereinthe tool member controlling lever means is provided with spring meansfor yi'eldably retracting the same to normal initial position.

4. In a tool for the purposes described, a. head member having an axialshank, said head member and shank being adapted to be rotated about thelongitudinal axis thereof, said head member and shank having an axialwire receiving bore and diametrically aligned slideway passages radialto said bore, opposed tool members slidably mounted in said slidewaypassages, a lever member for each tool member pivotally connected withsaid head member adjacently below said slideway passages, each levermember having a short upper arm cooperative with the tool member servedthereby for moving the latter into and out of operative engagement witha wire inserted in said bore, and each lever member having a relativelylong and weighty lower arm adapted to respond to outswinging centrifugalforce when the head member is rotated, whereby to swing the upper arm indirection to move the tool member served thereby into operative wireengaging position.

5. In a tool for the purposes described, a head member having an axialshank, said head member and shank being adapted to be rotated about thelongitudinal axis thereof, said head member and shank having an axialwire receiving bore and diametrically aligned slideway passages radialto said bore, opposed tool members slidably mounted in said slidewaypassages, a lever member for each tool member pivotally connected withsaid head member adjacently below said slideway passages, each levermember having a short upper arm cooperative with the tool member servedthereby for moving the latter into and out of operative engagement witha wire inserted in said bore, each lever member having a relatively longand weighty lower arm adapted to respond to outswinging centrifugalforce when the head member is rotated, whereby to swing the upper arm indirection to move the tool member served thereby into operative wireengaging position, and spring means for retracting said lower armswhereby to return said lever members and the tool members served therebyto normal initial positions when rotation of said head member isinterrupted.

6. In a tool for the purposes described, a head member having an axialshank, said head member and shank being adapted to be rotated about thelongitudinal axis thereof, said head member and shank having an axialwire receiving bore and diametrically aligned slideway passages radialto said bore, opposed tool members slidably mounted in said slidewaypassages, a primary lever member for each tool member pivotallyconnected with said head member adjacently below said slideway passages,each primary lever comprising an upper arm and a lower arm, said upperarm terminating in a cam finger cooperative with the tool member servedthereby for moving the latter into and out of operative engagement Witha wire inserted in said bore, a cross-head slidably mounted on the shankof said head member, secondary lever members respectively pivoted to theends of said cross-head, and weighty knuckle connections to pivotallyinterconnect corresponding secondary lever members and the lower arms ofsaid primary lever members, whereby said connected lever members areadapted to respond to centrifugal force for movement in direction to ad-Vance the tool members served thereby into operative wire engagingpositions.

'7. In a tool for the purposes described, a head member having an axialshank, said head member and shank being adapted to be rotated about thelongitudinal axis thereof, said head member and shank having an axialwire receiving bore and diametrically aligned slideway passages radialto said bore, opposed tool members slidably mounted in said slidewaypassages, a primary lever member for each tool member pivotallyconnected with said head member adjacently below said slideway passages,each primary lever comprising an upper arm and a lower arm, said upperarm terminating in a cam finger cooperative with the tool member servedthereby for moving the latter into and out of operative engagement witha wire inserted in said bore, a cross-head slidably mounted on the shankof said head member, secondary lever members respectively pivoted to theends of said cross-head, weighty knuckle connections to pivotallyinterconnect corresponding secondary lever members and the lower arms ofsaid primary lever members, whereby said connected lever members areadapted to respond to centrifugal force for movement in direction toadvance the tool members served thereby into operative wire engagingpositions, and spring means connected between the joined ends of saidprimary and secondary lever member sets whereby to retract the same andthe tool members served thereby to normal initial positions whenrotation of said head member is interrupted.

8. A tool for the purposes described as defined in claim 7, wherein saidtool members are provided at their operative ends with abrasive grindermembers.

ARTHUR P. BASS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

